The present invention generally relates to an system for and method of assembling automotive vehicle components. The invention particularly relates to a system for and method of controlling assembling of automotive vehicle components, in which at least one series of assembly lines is used in common for assembling various models and/or specifications of vehicles. More specifically, the invention relates to a system for and method of controlling an assembling system having at least one assembly line for vehicle bodies used as a common assembly line for assembling various models and/or specifications of vehicle bodies.
In automotive vehicle factories, series common assembly lines are used for assembling various models and/or specifications of automotive vehicle components. For example, in lines for assembling various models and/or specifications of vehicle bodies, there is a series including at least a common floor assembly line, a body assembly line and a body assembly finishing line for assembling various models and/or specifications of vehicle bodies. Generally, the series of assembly lines includes a special treatment line for vehicle bodies having special specifications. Such vehicle body assembling systems have used instruction papers containing information and instructions for selecting the line to be used, necessary parts, and processing procedures in accordance with production schedules or plans for the automotive vehicle components. The instruction papers are delivered to each assembly line in the system. On each line, workers sequentially arrange the respective parts which are applied to respective models and specifications of vehicle bodies, according to the instructions in the instruction papers, and operate assembling machines employed in the line to carry out the assembling operations. After finishing the assembling operation required in the line, the workers select the next line to process each specified model and vehicle body specifications and send the vehicle thereto according to the instruction papers.
However, in such system, where the workers of each assembly line previously arrange the parts to be assembled into the vehicle body in order, according to the instructions contained in the instruction paper, it is necessary to check the model and vehicle body specifications forwarded from the prior line, to see whether or not the model of the vehicle body forwarded is correct relative to the instructions.
Thereafter, the assembling operation is performed in accordance with the instructions contained in the instruction paper. After completing the required assembling operation, the workers in the line again check the assembly to confirm that the correct parts are being assembled and that the operations are correct. The assembly is then forwarded to succeeding lines, selected according to the instruction papers. Such checking must be made in each of the assembly lines, resulting in inefficiency of assembling system of the vehicle bodies.
Further, in the vehicle body assembly lines, there may often arise a necessity to force a body of unexpected models and specifications out of the order contained in the instruction papers into the line. Such necessity may arise, for example, by a new and special order from the customer. In such a situation, the special order vehicle body is often assembled prior to standard models and specifications of vehicle bodies to comply with the customer's request. Such special vehicles are thus entered into the assembly lines out of the order defined in the instruction papers. In this case the workers are required to visually detect or find such a vehicle body, before directing it into the assembling operation.
When the workers detect or find the aforementioned special models and specifications for the vehicle body, they must arrange respective parts to be applied thereto and perform the assembling operation in accordance with the procedure or specification designated in the specific vehicle body. In this case, serious confusion may occur to each assembly line. Further, if some assembly lines neglect to detect or find that the vehicle bodies are not of the instructions in the instruction papers and continue the assembling operation according to the instruction papers, unacceptable vehicle bodies may be produced.
To avoid such mis-assembling, that the workers of each line must detect the models and specifications of the vehicle bodies to be assembled and compare the same with that designated in the instruction papers for confirmation. Thereafter, each part to be assembled in the line is selected and used in the assembling operation, according to the specification and procedures included in the instruction papers.
In such conventional systems, it is required for each worker to possess an ability to distinguish the models of the vehicle bodies which are forwarded, in practice, to the assembly line one by one. It is difficult to distinguish slight differences in specifications of the vehicle bodies, at a glance. As a result, the assembling operation may be rather slow, resulting in inefficiency and low-productivity of the assembly line. The level of the labor skill must also be higher in order to reliably distinguish and recognize the various types of informations. Serious problems may arise due to the lack and high cost of skilled laborers.
In such a conventional system, since, distinguishing of the models and/or specification of the vehicle bodies relies upon the ability of human labor, the workers' energy might be unnecessarily exhausted. This may also cause possible mistakes in distinguishing the models and specifications of the body and of assembling operations.
In recent years, there has been provided a centralized computer control system for assembly lines, such a system being called a "tracking system". In this system, the instruction papers are replaced by instructions and information derived from the computer.
Information relative to the order of the vehicle bodies to be worked on by the assembly lines, models and specifications of respective bodies, necessary parts, order of processing and so on are supplied to the computer. The computer generates information and instruction signals which are fed to the respective areas.
To provide sufficient and sucessful controlling operations, large, high capacity computers are required which may significantly increase the cost of the assembly facilities. Further, employment of large computers may also require incidental facilities, for example an air-conditioning system.
Although the computerized controlling system for assembly lines can reduce the responsibility of the workers and can raise reliability of operation, it is still complicated with the computer system to keep track of changes in the order of assembling the bodies which may be caused by forcing in or taking out a body unexpectedly. Namely, if the necessity for forcing in or taking out of a special model, standard and/or specifications of the vehicle body arises, the instruction or information signal should be fed back to the computer to correct stored information therein. Therefore, the computer in the prior system cannot respond to a change in a given order according to a previous input order.
By using a larger or more complicated computer system for controlling the assmbly lines, it may be possible to improve efficiency of the assembling operation. However, one can also expected increased costs for the computer itself and its facilities, as well as complicated operation. Further, in such a computerized controlling system, if there is some accident or damage even at one terminal of the system, the accident or damage affects the whole system. Furthermore, if damage, accident or malfunction occurs inside the computer, all the assembly lines are stopped.
The present invention removes the aforementioned disadvantages or inconveniences in the prior control systems by including all the necessary information and instructions with respect to a model standard and/or specifications of the vehicle body on the respective vehicle bodies, thereby making it possible to respond easily to any change of a given order for performing an assembling operation.